Homing issues with minor position_min and position_endstop for y axis

[pellcorp]

So an example:

[stepper_y]
position_min: -2
position_endstop: -1

So the current test:

{% if y_position_endstop > y_position_min %}

Will result in:

G1 Y-{homing_move_away_y } F1200

What that test is about is seeing if we are homing to the min side of the axis or the max side, the current test is very fragile

Although we could try and hide it by changing the test to:

{% if y_position_endstop > (y_position_min + homing_move_away_y) %}

But actually failing to home is probably the best outcome cos im not sure what a mismatched position_endstop and position_min would do if ignored.

[pellcorp]

What we could do is throw an error in homing flagging the fact that the position_min and position_endstop are not equal but differ less than the homing_move_away_y, that might actually be the better play here.